The invention is concerned with a projector which emits a high powered highly concentrated beam that extends over a significant length of say 1000 to 2000 meters or more. (Such a projector is sometimes also referred to as “a search light” or a “torch”). The projector has particular applicability for military and security purposes and is referred to herein as “a military projector”.
Known military projectors comprise a tubular housing that contains a high intensity lamp behind which lamp is a reflecting mirror and before the lamp is a biconcave lens. There is further a positive meniscus lens spaced from the biconvex lamp and located near the front of the housing. Perforce the distance between the biconvex lens and the meniscus lens is substantial Iii order to concentrate the light beam emitted by the military projector. As the length of the housing extends for the full length of the distance between the lamp and the positive meniscus lens, the mass of the projector is significant. Such a military projector as herein referred to as a “military projector of the kind set forth”.
For certain military purposes the projector requires to be of reduced mass and known military projectors are generally too heavy for convenient use in such purposes.